1. Field of the Invention
The present invention relates broadly to the type of hitch which is used to connect the end of a towing vehicle, such as a pickup truck, to the forward end of a towed vehicle, commonly referred to as a trailer. Normally the towing vehicle will have a ball on or adjacent a rear bumper of the towing vehicle, whereas the trailer will have a forwardly projecting arm which includes a socket that is capable of enveloping the ball on the towing vehicle. More particularly, the present invention relates to a locking device which cooperates with the arm and the structure on the towing vehicle associated with the ball for locking the arm into engagement with the ball.
2. The Prior Art
A preliminary search was conducted on the present invention and the following listed patents were uncovered in the search:
______________________________________ Patent No. Inventor Issue Date ______________________________________ 2,571,349 Eckles 10-16-51 2,834,611 Chenette 05-13-58 4,082,311 Hamman 04-04-78 4,773,805 Krahling 09-27-88 4,958,847 Williams 09-25-90 5,072,964 Schule 12-17-91 5,154,440 Dolan 10-13-92 5,378,008 McCrossen 01-03-95 ______________________________________
McCrossen U.S. Pat. No. 5,378,008 is described as having a "theft prevention feature". Plate 60, attached to tongue 11, has an opening 68 which surrounds a lock nut 25.
Dolan U.S. Pat. No. 5,154,440 shows a coupler lock 10 pivoted to a coupler 20.
Williams U.S. Pat. No. 4,958,847 shows a tow bar assembly which includes coupling chains and which also shows a locking cable 132 in FIG. 21.
Krahling U.S. Pat. No. 4,773,805 shows a safety coupling pin and a chain 30.
Eckles U.S. Pat. No. 2,571,349 shows a pivoted member 28 in FIG. 4 with padlock 32.
Schule U.S. Pat. No. 5,072,964 shows a safety cable 6 with ball and socket.
Chenette U.S. Pat. No. 2,834,611 shows a pivoted arm 14 with a recess 15 for receiving a nut 8 attached to a ball 5. A removable pin 17 will hold the arm 14 in the position shown in FIG. 1.
Hamman U.S. Pat. No. 4,082,311 shows a pivoted lock plate 24 and padlock 62.